Press for the production of artistic prints and embossings



March 5, 1929. GRUNBERG 1,704,567

PRESS FOR THE PRODUCTION OF ARTISTIC PRINTS AND EMBOSSINGS Filed Sept. 21, 1927 Patented Mar. 5,1929.

UNITED STATES v 1,704,567 ATENT OFFlCE.

JosEF eniinniine, or BERLIN, GERMANY.

PRESS FOR THE PRODUCTION OF ARTISTIC PRINTS AND EMBOSSINGS.

Application filed September 21, 1927, Serial No. 221,066, and in' Germany September 28, 1926.

My United States Patent No. 1,547,871 relates to a printing press for the production of artistic prints and embossings in which a yielding material to be printed upon is pressed against the original piecec opp er plate,

lithographic stone, woodcut or the like-consisting of unyielding material, by means of an elastic wall of a pressure receptacle.

. According to my Patent No.- 1,547,871 the press platen which carries the'original piece, may in some cases, also be arranged so as to have a liquid containing chamber which is closed by means of an elastic wall. The original piece rests on this elastic wall. The liquid 1 containing chamber is to be filled with a certain amount of the. liquid, which forms the counter bearing for the working pressure actingfrom above. "Because of the changes in temperature and possibly leaks, the quantity,

2 of liquid contained in the liquid containing chamber was reduced, whereby the elastic wall which carried the original piece or matrix was bent and deformed downwardly and ing the process of printing.

The disadvantage above described is to be overcome by this invention by a further imstance, be connected with the chamber of the press platen by'means of a pressure pipe, so that during each generation of pressure in the pressure chamber, the elastic wall of the press platen is also put under pressure from below. For the same purpose however, and also by making use of a certain amount'ot liquid in the liquid. containing chamber of the press platen. the capacity of the liquid containing chamber can be made alterable, o that upon a reduction of the quantity of the liquid the elastic wall of the press platen is always kept under an equal pressure. For this purpose an adjustable piston provided in the liquidcontaining chamber of the press platen can bemade use of. The adjustment of the piston can be done automatically by means of the lifting of the press platen, required during'the process of printing. a v

Thereby, that according to this invention did not give a suflicient counterbearing durthe elastic wall of the press platen is pressed against its seat with a fixed pressure, it is no longer necessary as'in the press according to my above mentioned patent, to have the elastic wall pressed against itsseat by'means of a pressurering on which acts the elastic wall of the upper pressure container. -Hereby the surface occupied by the pressure ring on the upper and lower elastic'walls is made vacant for use as a pressing surface, so that with an elastic wall of an equal size larger original pieces, or the like, can be used.

In the accompanying drawing three different modified examples of the invention are illustrated in vertical cross sections.

In the form as shown in Figure 1 the upper pressure container 3 of the press is closed on its under side by means of an elastic wall 5, for instance, a rubber plate. Below the pressure container the press platen 17 is provided in such a manner, that it can be raised and lowered, having its interior space 24 closed above by means of an elastic wall 25 for instance, a rubber plate. The latter is, -for example, pressed against the under side of the flanges 61 by means of the pressure springs 60. The interior space of the upper pressure container 3 is in direct connection with the space 24 of the press platen 17 by means of the hose or pipe 62. Therefore, when a pressure is generated in the pressure container '3 by pumping a liquid into it, the same pressure is created in the space 24 under the rubbcr plate 25 on which the original piece and .the material that is to be acted upon lies.

this cylindrical space a piston 64 is provided which can be adjusted by meansof the screwspindle 65. The latter can be screwed in a thread-part 65 provided in one side of the press platen. The entire space for the liquid can be hereby reduced when the quantity of the liquid is diminished, so as to always have an equal pressure acting upon the elastic wall 25 I In the example shown in Figure 3, the screw-spindle 65 of the piston 64 is rovided with a nut 66 with which one arm o the bell crank lever 67 is engaged. The latter is pivoted on the pin 68 thatis provided on the pressplaten 17 The free arm of the lever 67 lies in reach of an adjustable stop 69, which is provided on the upper pressure container 3. lVhcn the press platen 17 is moved upwards against the elastic wall 5 during the working process, the lever 67 strikes against the stop 69, whereby the spindle with the 64 is moved inwardly, so that the elastic carrying wall 25 is correspondingly under pressure. A pressure spring which is loosely inserted, serves the purpose of bringing the piston 64 back to its initial position, after the press platen 17 has moved downward. By turning the spindle 65 in the nut 66 the piston can be adjusted by hand.

It is expedient to have the interior pressure in the space 24 of the press platen 17 2 so pro portioned, that the'elastic wall 25 becomes slightly arched outwardly, as it is always pushed back under the pressure of the upper wall 5 Through this pressure which is brought to bear onto the liquid in the-space 24 from above, the pressure with which the liquid presses the carrying wall 25 against its seat is increased, that is to say, since a liquid is an incompressible medium, any pressure, as high as it may be, which acts upon the elastic wall 25 from above, produces an equal pressure within the liquid space 24 and with this pressure theelastic wall 25 is therefore pressed against its seat from below.

I claim:

1. A press .for the production of artistic prints and embossings, comprising in combination, a press platen arranged to form a liquidcontainer having an elastic carrying wall for the original piece, with an upper pressure container having an elastic wall and means for regulating the pressure under and against the elastic wall of the said press platen, substantially as set forth. i

2. A press for the production of artistic prints and embossings, comprising in combination, a press platen arranged to form a liq- ,i

uid container having an elastic carrying wall for the original piece, with an upper pressure container having an elastic .wallgand means for reducing the space in the interior of the said liquid containing press platen, substantially as set forth.

3. A press for the production of artistic prints and embossings, comprising in combination, a press platen arranged to form a liquid container having an elastic carrying wall for the original piece, with an upper pressure container having an elastic wall, the said liquid containing press platen having a piston in a cylindrical space adjoining the interior space of the press platen, and movable to reduce the space in the interior of the press platen.

4. A press for the production of artistic prints and embossings, comprising in combination, a press platen arranged to form a liquid container having an elastic carrying wall for the original piece, with an upper pressure container having an elastic wall and means to automatically regulate the pressure under the elastic wall of the said liquid containing I press platen, substantially as set forth.

5. A press for the production of artistic prints and embossings, comprising in combination, a press platen arranged to form a liquid container having an elastic carrying wall for the original piece, with an upper pressure container having an elastic wall,-the said liquid containing press platen having a piston in a cylindrical space adjoining the interior space of the said press platen, the said piston having a threaded spindle and anut adapted to engage with one arm of an angle-lever pivoted on a pin provided on the said press platen, the free arm of said angle-lever being adapted to come into contact with an adjustable stop provided on the said upper pressure container so as to move the said piston inwardly when the said liquid tontaining pi'ess platen is raised and a pressure spring to push back the said piston to its initial position when the said liquid containing press platen is lowered, substantially and for the purpose as described.

In testimonywhereof I have aflixed my signature.

J OSEF GRUNBERG, 

